Burning 6400M!

Tonight I was working FT-8 with my 6400m. I was able to work a few stations, suddenly a burning smell. Powered Everything down, smell seems strongest near the ethernet port. Was only using about 50w, matched into a Palstar AT-Auto. Flex is only 1 week old! :( Radio still appears to function. Ive worked hundreds of stations with my FTDX-3000 in same arrangement with no issues.

Dave
Hope your not using the Internal Antenna Tuner
And the External Antenna Tuner at the same tine
This can stress the Filter Networks and possibly
Damage them
Only use One Tuner
If your 6400M has no internal tuner then
I am not sure what the issue is
73 Mike

The two tuner issue has been discussed before. There is no problem if done correctly. Tune external with radio in bypass. If match not achieved then tune internal to bring into match. I suspect Dave has only external tuner.
73 Bob W5TX

All I have to say is Flex is amazing. They are sending me a new radio! I do want to make sure nothing environmental could have an impact on this. Does anyone use any isolation devices, ferrites..etc Just want to protect the radio anyway I can. I have used many radios in this shack even with an amplifier and have never had an issue.

Dave,I have nothing but praise for Flex Radio. I am, also, using my 6600 with the Palstar HF-Auto tune, along with the Palstar LA-1K amplifier or the Ameritron 600S, and have not encountered any problems. With the HF-Auto tuner, I never need to engage the internal ATU.

I do use ferrites on most of my connecting cables inside the shack, plus I have a 1:1 balun at the antenna feed point on all my antennas. I use mix 31 for the ferrites.

I have ferrites on just about every interface cable to the Flex and had them on the Elecraft radios that I replaced.. I was having some RFI issues due the fact that I bring balanced feeders right into the shack and tune them with old E F Johnson match boxes.

There are a series of articles written by K9YC and W1HIS about common mode chokes. They are archived on the internet. The cores that they use are available from DX engineering, Pro Audio, and Mouser. Mouser has the lowest prices, however, you must know the correct "Fair-rite Part number if ordering from them ( the articles have the part numbers mentioned). I use the larger clamp on cores with multiple turns through them rather than several smaller cores (its the square of turns ratio). I also have cores on the HDMI cables ( both ends) and either net cables. I also use the 2.4 inch mix 31 cores if the cable ends will go through. I keep a few extra cores on hand just in case.

By the time you spend lots of $$ on cores and clamps plus shipping and then spend days or weeks of reading, posting and learning how to wind them properly you can simply install these bads boys and call it a day ! They are a bargain at $49 a pair. Better yet buy the 10 pack and get free shipping. If you dont need 10 then split the cost with a friend. I am not a DXE spokesperson or affiliated with DXE in any way.

PS - Yes, I have spent lots of $$ and countless hours learning and intsalling chokes and clamps on every wire and cable in my shack and it really helped my station perform better. Just trying to make it easy for you. However, if you want to learn a new skill then you have some good advice in this thread. Also, take a look at HamNation #386 and #390. See how the master himself does it !

Your assuming RF gets only thru Ethernet cable but
It can travel down other lines, Coax Lines, Power Supply
Audio cables, radiation back into Shack, etc
Any cables attached to Rig can allow RF into Rig
To damage it
RF can travel down Coax Lines and get back into Rig
73 Mike

You are absolutely right ! I was only suggesting an easy way to place chokes on ethernet cables. But every wire and cable in the shack and beyond needs to be addressed. It's quite an effort to do it correctly !

Joe, have you had any experience with the DX engineering devices? Seems like they use a different technology to filter or isolate. Would you need to buy these for every device? Thanks so much for the suggestion. I am just trying to do everything I can to make sure the Flex is protected. I do not know if external environmental variables had anything to do with it, but I want to make sure I am doing the best I can to prevent anything from happening.

No, not with these new Ethernet chokes. However, I do have some of their gear and it is top notch. Tim Duffy (K3LR) really knows his stuff when it comes to building a world class station and preventing RFI and damage to equipment. Give them a call and talk to them about your situation. Operators are standing by !

Just because you think the smell was "strongest" near the ethernet port doesn't mean you should spend $hundreds on a bunch of over-priced filters. If RF burned up your ethernet port, it is all but certain that the port would no longer link-up. So I don't think that is what happened.

Most likely, a manufacturing defect is causing a failure in the PA, or a 1/10000 part failure occurred in a benign spot. Low-voltage tantalum caps used for power supply bypass have a tendency to fail and when they do - it's like a roman candle going off.

I agree, I strongly believe this could have been a fluke. What was strange to me is the port itself had the strong smell of burning pcb which is far away from the PA section. Im really doing this in the spirit of good practice. If for any reason this where to happen again, I can prove to Flex I am doing everything I can on my end to maintain a good operating environment.

The fiber link to the switch provides isolation from the long ethernet cables throughout the house and from the server room. Any power surges, RFI or lightning induced surges would be stopped at the fiber link and before they get to the switch.

The switch is located just inches away from the Flex 6700 and the shack PC. So by using a switch I get protection for the radio, PC and anything else I may connect to the switch. The cat5 jumper from the switch to the radio is very short ( about 18 inches) but I also have ferrites on it to suppress any RF that may be in the shack. (Probably not needed but suspenders and a belt).